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.AJ'1II3 TE3]EL'.L E. STRIPPEL, OF NEW YORK, N. Y.

METHOD OF PRODUCING A STENCILING FABRIC.

No Drawing.

long fiber fabric, such as Japanese paper,

and it is treated with solutions including gelatin, glycerin, bichromateof potash and calcium chlorid in substantially the relative proportionsherein specified.

In carrying out the method, I soak 14 oz. of chemically pure gelatin in5 pints of water for about one hour. This solution is then heated on awater bath to about 190 F. until the gelatin is thoroughly dissolved.The solution is then strained off into a. heated vat, and 15 oz. ofchemically pure glycerin is added to the solution and the wholemaintained at a heat of about 190 F. in said vat. In a separate vessel,I dissolve 2% oz. of bichromate of potash in 5 pints of water and heatthe solution to about 190 F. and then pour the same into the vatcontaining the solution of gelatin and glycerin. The solution is thenthoroughly agitated and kept at about 190 F. and away from the influenceof light.

Two sheets of grade A, Japanese paper are pasted on to a holder, as forinstance, with shellac, and are treated to the solution in the vat bythoroughly saturating the paper therewith. The two sheets are thuscombined to form a sheet of double thickness. The so saturated sheet isthen dried in the sunlight or a good are light. After the sheet isdried, it is cutfromthe holder and run through a bath of warm Water forthe purpose of washing off the excess of bichromate and chromic oxidproduced. The sheet is then run through a fifteen per cent.

Specification of Letters Patent.

Patented Aug. 15, 1916.

Application filed November 22, 1912. Serial No. 732,992.

solution'of calcium chlorid for the purpose of rendering the sheethydrous. The sheet is then partially dried, and while still damp issubjected to heat and pressure, as for instance, by passing the sheetthrough heated calender rolls exerting the desired pressure upon thesheet. The sheet is then cut into the proper sizes for use and attachedto the proper frames as is usual. The fabric thus formed is very strongand will not readily break or tear and will keep moist and soft.

While I have described the use of J apanese paper, other fibrousmaterials might be.

utilized,such, for instance, as linen, cheesecloth, silk, etc.

What I claim is: I

1. The method of producing a fabric for stenciling and similar uses,consisting in first subjecting the fabric to treatment in a heatedsolution including gelatin, glycerin and bichromate of potash insubstantially the relative proportions specified in which the glycerinby weight exceeds the gelatin, then to a treatment in warm water, andthen to a treatment in a substantially fifteen per cent. solutionofcalcium chlorid.

2. The method of producing a fabric for stenciling and similar uses,consisting in first subjecting the fabric to treatment in a heatedsolution including gelatin, glycerin and bichromate of potash insubstantially the relative proportions specified in which the glycerinby weight exceeds the gelatin, and away from the influence of light,then drying the fabric in the light, then submit ting the fabric. to atreatment in warm water, then submitting the fabric to treatment in asubstantially fifteen per cent. solution of calcium chlorid, and finallysubjecting the. fabric to heat and pressure'for drying and finishing thesame.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two witnesses, this twenty first day of November1912.

ALBERT E. STRIPPEL.

Witnesses:

F. GEORGE BARRY 'HENRY C. THIEME.

